POS0985 MILD PSORIASIS SEEMS OFTEN UNDERDIAGNOSED IN PATIENT WITH AXIAL SPONDYLOARTHRITIS
Authors: L. Van Marle, A. Rondags, B. Horvath, F. Wink, S. Arends, A. Spoorenberg
Journal: Annals of the Rheumatic Diseases (2022)

Background Axial spondyloarthritis (axSpA) is known to be associated with several extra-skeletal manifestations, including the inflammatory skin disease psoriasis. It is important to recognize and diagnose psoriasis timely in axSpA to provide the most optimal treatment and outcome for both axSpA and psoriasis. Furthermore, in patients suspected of axSpA, it may add to making the axSpA diagnosis. Objectives To explore the self-reported prevalence of psoriasis in axSpA patients using a questionnaire with prototypical color pictures, and to compare this with the prevalence of a verified diagnosis. Secondly, to explore if there are differences in disease and patient characteristics between axSpA patients with and without self-reported psoriasis. Methods All patients from the Dutch Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort included before June 2016, were sent a questionnaire with self-screening psoriasis questions. The applied self-diagnostic psoriasis question “Do you have psoriasis?” was supported with the following brief elucidation: “Psoriasis is a skin disease in which red and scaly patches develop on the body, especially on the elbows, knees and hairy head. The nails can also be affected, and sometimes there are joint complaints.” In addition, to enable patients to self-assess the presence of psoriasis more accurately, prototypical color pictures of psoriasis lesions were added. Patients could reply with “no”, “yes, in the past” or “yes, currently”. In patients who indicated having psoriasis symptoms, a medical record check was done to verify previously diagnosed psoriasis. The diagnosis of psoriasis was considered valid if it was described in the medical record by a dermatologist or rheumatologist. Results Of the 592 questionnaires sent, 471 (79.6%) were returned, of which 448 (75.7%) were eligible for analysis. Of these 448 included patients, 79% were diagnosed with AS and 21% with nr-axSpA, mean (±SD) age was 50.1±12.7 years, 64% were male, median (IQR) SpA symptom duration was 21.0 (12.0-32.0) years, 79% were HLA-B27 positive and mean ASDAS CRP was 2.2±1.0. History of peripheral arthritis, enthesitis and dactylitis was present in 39%, 20% and 7% of patients, respectively. The male-female ratio between the 448 included and 144 excluded patients was similar. Excluded patients were significantly younger (43.3 ± 13.6, p&lt;0.001). Of the 448 respondents, 58 (13%) had a positive self-screening for psoriasis symptoms, currently or in the past. In 28 (48%) of these 58 patients, psoriasis diagnosis could be verified by medical records, resulting in a confirmed psoriasis prevalence rate of 6.3%. AxSpA patients reporting psoriasis symptoms without a verified diagnosis mentioned more often mild than moderate or severe psoriasis symptoms (25% vs. 3%, p=0.02) and their psoriasis lesions were less often located on the torso area (3% vs. 18%, p=0.04), intergluteal cleft (0% vs. 25%, p=0.02) and legs (7% vs. 43%, p&lt;0.01) compared to axSpA patients with a confirmed diagnosis. Of the 31 axSpA patients who reported currently active psoriasis (irrespective of confirmed diagnosis), 23 (74%) had only mild psoriasis symptoms. Conclusion Especially mild psoriasis seems often underdiagnosed in patient with axSpA according to a patient questionnaire with prototypical pictures of psoriasis lesions. This questionnaire could be beneficial in tracing patients with undiagnosed psoriasis in daily clinical practice, however further validation of this questionnaire is needed in daily clinical practice. Disclosure of Interests Laura van Marle: None declared, Angelique Rondags: None declared, Barbara Horvath Paid instructor for: Janssen-Cilag, AbbVie, Consultant of: Janssen-Cilag, AbbVie, Novartis Pharma, UCB Pharma, Leo Pharma, Celgene, Akari therapeutics, Philips, Roche, Regeneron, Sanofi, Grant/research support from: Janssen-Cilag, AbbVie, Novartis Pharma, Solenne B.V., Celgene, Akari therapeutics, Freke Wink: None declared, Suzanne Arends Paid instructor for: AbbVie, Consultant of: AbbVie, Novartis Pharma, Pfizer, UCB Pharma, Lilly, Grant/research support from: Novartis Pharma, Pfizer, Anneke Spoorenberg: None declared